Production of lipase free of citrinin by Penicillium citrinum

Lipase (Glycerol ester hydrolase E.G. 3.1.1.3) from a Brazilian strain of Penicillium citrinum free of the mycotoxin citrinin has been investigated. Citrinin production was inhibited by using culture medium containing olive oil, soybean oil and corn oil as carbon sources. Potassium concentration and pH play an important role in citrinin production. Potassium concentration lower than 30 mM and pH below 4.5 inhibited the mycotoxin production. P. citrinum produced lipase free of extraneous proteins and citrinin when cultured using, as nitrogen source, ammonium sulphate (lipase activity of 7.88 U/mg) and yeast extract (lipase activity of 4.95 U/mg) with olive oil as carbon source. This data is relevant to the larger scale production of lipases for food technology applications, from Penicillium citrinum.     

产脂肪酶细菌RYXP的诱变选育及突变株产酶条件优化

以"凤丹"牡丹根际土壤中分离筛选到的产脂肪酶菌株Pseudomonas sp. RYXP作为出发菌株,对其进行了紫外线诱变选育,并采用单因素试验和正交试验方法对活性最强正突变株的产脂肪酶基本特性进行了测定。结果表明,出发菌株Pseudomonas sp. RYXP的紫外线诱变最佳条件为:15 W紫外灯30 cm距离照射1 min;将产脂肪酶活性最强的正突变菌株编号为RYXP-3,单因素试验表明RYXP-3产脂肪酶适宜的碳源为玉米淀粉,适宜氮源为豆饼粉,适宜的磷酸二氢钾含量是0.3%,适宜的初始pH值为7;正交试验表明RYXP-3的最佳的产酶培养基成分组成是:玉米淀粉7%,豆饼粉3%,磷酸二氢钾0.3%,初始pH值为8。在优化方案A1B2C2D3产酶条件下,突变株RYXP-3最高的产酶活性达到56.1 U/mL。突变菌株RYXP-3可作为产油牡丹"凤丹"专用促生菌肥开发的备选资源菌株。     

Optimization of extracellular lipase production by Geotrichum sp. using factorial design

Response surface methodology was employed to study the effects of carbon source (soy oil, olive oil and glucose) and nitrogen source concentrations (corn steep liquor and NH(4)NO(3)) on the lipase production by Geotrichum sp. The experiment included a 2(4) central composite rotatable design (CCRD) and four others 2(3) CCRD. According to the responses from the experimental designs, the effects of each variable were calculated and the interactions between them were determined. The response surface methodology was applied for the optimization of the nutrient concentrations in the culture medium for the enzyme production, at 30 degrees C. The optimum medium composition for lipase production by Geotrichum sp. was ammonium nitrate 2.1-2.5%, corn steep liquor 13-15% and soy oil 0.6% as carbon source, which lead to a lipase activity of about 20 U/ml. Using olive oil as carbon source, the optimum composition was ammonium nitrate 0.8-1%, corn steep liquor 13-15% and olive oil 0.6%, leading to an activity of 17 U/ml.     

Lipase production by Trichosporon fermentans WU-C12, a newly isolated yeast

From the soil samples of various locations, 245 strains of microorganisms were isolated by the enrichment culture method using olive oil as a carbon source. Of these microorganisms one deuteromycotinous yeast was the best producer of extracellular lipase, and the strain WU-C12 was identified as Trichosporon fermentans from the morphological and taxonomical properties. When cultivated at 30°C for 4 d in the medium containing 8% (w/v) corn steep and 3% (v/v) olive oil as sources of nitrogen and carbon, T. fermentans WU-C12 produced 126 U/ml of extracellular lipase. When 3% (v/v) tung oil was used instead of 3% (v/v) olive oil, 146 U/ml of the lipase was produced. Although lipase production decreased to 40 U/ml by the addition of 2% (w/v) glucose to the corn steep-olive oil medium, the strain WU-C12 produced 34 U/ml of lipase in the medium containing 2% (w/v) glucose instead of 3% (v/v) olive oil. On the other hand, T. fermentans WU-C12 could grow and produce lipase in the medium containing n-paraffin as a carbon source.     

Extracellular lipase production by a sapwood-staining fungus,Ophiostoma piceae

The extracellular lipase production of a sapwood-staining fungus, Ophiostoma piceae, grown in liquid media, was optimally active at pH 5.5 and 37°C. Although glucose, fructose, sucrose, starch and dextrin, as carbon sources for growth gave similar mycelial yields, which were higher than those obtained with arabinose, galactose or raffinose, the cells growing on those carbohydrates produced little extracellular lipase. However, both high biomass and lipase activity were obtained when plant oils (olive, soybean, corn, sunflower seed, sesame, cotton seed or peanut) were used as carbon sources. Among the nitrogen sources examined, Casamino acids gave the best growth, whereas (NH₄)₂SO₄ gave the best lipase production. The highest lipase productivity seen was obtained in a medium with olive oil as carbon source and a combination of (NH₄)₂SO₄and peptone as nitrogen source.The authors are with Forest Products Biotechnology, Department of Wood Science, Facully of Forestry, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada     

Effect of culture conditions on lipase production by Fusarium solani in batch fermentation

Lipase (Glycerol ester hydrolase EC 3.1.1.3.) from a Brazilian strain of Fusarium solani FSI has been investigated. The effect of different carbon sources and trace elements added to basal medium was observed with the aim of improving enzyme production. Lipase specific activity was highest (0.45 U mg(-1)) for sesame oil. When this medium was supplemented with trace elements using olive oil, corn oil and sesame oil the lipase specific activity increased to 0.86, 1.89 and 1.64 U mg(-1), respectively, after 96 h cultivation without any considerable biomass increase. The Km of this lipase using pNPP (p-nitrophenylpalmitate) as substrate, was 1.8 mM with a Vmax of 1.7 micromol min(-1) mg protein(-1). Lipase activity increased in the presence of increasing concentrations of hexane and toluene. In contrast, incubation of this enzyme with water-soluble solvents decreased its activity after 10% concentration (v/v) of the solvent. The lipase activity was stable below 35 degrees C but above this temperature activity losses were observed.     

Carbon source impact on Yarrowia lipolytica KKP 379 lipase production

The production of lipases by microorganisms is strongly influenced by the culture conditions. The optimum culture conditions for enzyme production are strain- and species-dependent. The aim of this study was to evaluate the impact of the carbon source used in the culture medium on the profile of lipases produced by Yarrowia lipolytica KKP 379. We observed a different pattern of extracellular and cell-bound lipase production, which was the highest in the early exponential phase. The extracellular lipase activity increased in the late exponential phase due to the lower accumulation of lipase molecules in cell walls. The best carbon source for extracellular lipase production by Y. lipolytica KKP 379 was olive oil. Glucose, dodecane and olive oil had a positive effect on biomass yield. Dodecane and/or glycerol utilization in microbiological lipase production was possible, but this process could not proceed without the addition of some activators such as olive oil in the cultivation medium.     

Polysaccharide production by a reduced pigmentation mutant of Aureobasidium pullulans NYS-1

AIMS: To isolate a reduced pigmentation mutant of Aureobasidium pullulans NYS-1 and characterize its cellular pigmentation plus its polysaccharide and biomass production relative to carbon source. METHODS AND RESULTS: Cellular pigmentation, polysaccharide levels and biomass production by the isolated mutant NYSRP-1 were analysed relative to carbon source. Cellular pigmentation of the mutant was lower than its parent strain using either carbon source. The mutant elaborated higher polysaccharide levels on sucrose than on corn syrup. The pullulan content of the polysaccharide synthesized and biomass production by the mutant rose as the carbon source concentration was increased. CONCLUSION: It is feasible to isolate a reduced pigmentation mutant from strain NYS-1 that exhibits elevated polysaccharide production using corn syrup as a carbon source. SIGNIFICANCE AND IMPACT OF THE STUDY: The mutant provides an advantage for commercial pullulan production because of its reduced pigmentation and enhanced polysaccharide synthesis.     

Influence of carbon and nitrogen sources on lipase production by a newly isolated Candida viswanathii strain

Microorganisms can produce lipases with different biochemical characteristics making necessary the screening of new lipase-producing strains for different industrial applications. In this study, 90 microbial strains were screened as potential lipase producers using a sensitive agar plate method with a suitable medium supplemented with Tween 20 and also a liquid culture supplemented with olive oil. The highest cell growth and lipase production for Candida viswanathii were observed in triolein and oleic acid when used as the only pure carbon source. Renewable low-cost triacylglycerols supported the best cell growth, and olive oil was found to be the best inducer for lipase production (19.50 g/L and 58.50 U). The selected conditions for enzyme production were found with yeast extract as nitrogen source and 1.5 % (w/v) olive oil (85.70 U) that resulted in a good cell growth yield (Y_X/S?=?1.234 g/g) and lipase productivity (1.204 U/h) after 72 h of shake-flask cultivation. C. viswanathii lipase presented high hydrolytic activity on esters bonds of triacylglycerols of long-chain, and this strain can be considered an important candidate for future applications in chemical industries.     

Lipase production by Serratia marcescens strain SN5gR isolated from the scat of lion-tailed macaque (Macaca silenus) in Silent Valley National Park, a biodiversity hotspot in India

An extracellular lipase-producing bacterium was isolated from a fecal sample of lion-tailed macaque (Macaca silenus), an endangered Old World monkey that is endemic to the Western Ghats of South India. Morphological, biochemical and molecular analyses identified the bacterium as Serratia marcescens. Production of lipase was investigated in shake-flask culture. Optimum tributyrin concentration of 1.5 % was found to be the most suitable triglyceride to increase lipase production (13.3 U ml^?1). The next best lipid source observed was olive oil (11.94 U ml^?1), followed by castor oil, coconut oil and palm oil. Analyzing the effect of different carbon sources on lipase production revealed that 2 % glucose yielded higher lipase production than the other tested carbon sources. Investigations on suitable nitrogen source for lipase production revealed that 2 % meat extract yielded higher lipase production. The most suitable trace element for maximum lipase production was zinc sulfate, followed by magnesium sulfate and copper sulfate. Partial characterization of the crude lipase revealed that pH 7.0 and a temperature of 40 °C gave optimal lipase activity. Enzymatic activity of the crude sample was retained over a wide temperature range (20–75 °C), and 70 % of enzyme activity was retained at 60 °C. Testing the effect of various organic solvents on lipase activity revealed that hexadecane increased lipase activity by 85 % over the control.     

溶剂稳定性蛋白酶产生菌Bacillus licheniformis YP1的发酵优化

溶剂稳定性蛋白酶产生菌Bacillus licheniformis YP1分离自油田土样。考察了碳源、氮源、金属离子等营养因素对YP1菌株发酵产溶剂稳定性蛋白酶的影响。YP1菌株发酵产胞外蛋白酶的最佳碳源为淀粉,果糖、甘露糖和乳糖显著抑制产酶;最佳氮源为酵母膏,干酪素、酵母粉和牛肉膏促进产酶,玉米浆和尿素显著抑制产酶。Mn^2＋可以显著促进酶活,Mg^2＋可以促进产酶,在初步优化的培养条件下,YP1菌株的胞外蛋白酶产量达980U。     

Isolation of a mutant strain of Pseudomonas sp ATCC 31461 exhibiting elevated polysaccharide production

A mutant strain of the bacterium Pseudomonas sp. ATCC 31461 that exhibited elevated production of the polysaccharide gellan on glucose or corn syrup as a carbon source was isolated. Gellan production by the mutant strain was about twofold higher than its parent strain on glucose or corn syrup after 48 h of growth, and about 1.4-fold higher after 72 h. An increase in biomass production was not correlated with enhanced gellan synthesis by the mutant strain. The increased gellan production by the mutant strain on either carbon source resulted in an increase in its culture medium viscosity and the viscosity of the isolated polysaccharide produced by glucose-grown cells. No differences in the glucuronic acid content of the polysaccharides produced by the mutant and parent strains were observed. Journal of Industrial Microbiology & Biotechnology (2002) 29, 185–188 doi:10.1038/sj.jim.7000278 Received 13 February 2002/ Accepted in revised form 20 May 2002     

Enhancement of lipase production from hydrocarbons by mutation of Trichosporon fermentans

Lipase high-producing mutants with petroleum products as carbon sources were successfully induced from Trichosporon fermentans WU-C12 by ultraviolet (UV) light irradiation. In the first mutation step, one mutant strain, PU-30, derived from strain WU-C12 was selected. The productivity of extracellular lipase of PU-30 reached 58 units (U)/ml in the medium containing kerosene, being approximately twice the productivity of the parental strain WU-C12. In the second mutation step, the mutant strain 2PU-18 was induced from strain PU-30. In medium containing kerosene, gas oil and liquid paraffin, the 2PU-18 produced 70 U/ml, 62 U/ml and 60 U/ml of extracellular lipase, respectively. When various n-alkanes (C₈-C₁₈) were used as carbon sources, the parental strain WU-C12 produced more than 20 U/ml of lipase only from C₉-C₁₂ alkanes, but 2PU-18 could produce more than 50 U/ml of lipase from C₈-C₁₈ alkanes. When cultivated for 3 days in medium containing liquid paraffin, the activity ratios of extracellular lipase to total lipase and the values of extracellular lipase activity per dry-cell weight were 0.44 and 0.65 U/mg for WU-C12, and 0.62 and 1.82 U/mg for 2PU-18, respectively. These results indicate that the mutant strain 2PU-18 is superior in both total lipase productivity and permeability of lipase to the parental strain WU-C12 when petroleum products are used as carbon sources. Correspondence to: S. Usami     

Strain improvement of Serratia marcescens ECU1010 and medium cost reduction for economic production of lipase

Industrial strain improvement plays a central role in the commercial development of microbial fermentation processes. The strain of Serratia marcescens ECU1010, a wild-type lipase-producer capable of stereospecific synthesis of a Diltiazem precursor, was subjected to physical mutation involving treatment by UV-irradiation for 30 s. A mutant strain, no. UV-01, showed enhanced lipase production, but lost the capability of producing red pigment (prodigiosin). The variant strain UV-01 had a 2.3-fold higher activity than the wild type and was stable in its enzyme production for ten serial transfers. For reduction of the fermentation medium cost, dried powder of corn steep liquor was used as an inexpensive substitute for beef extract in the medium. Dextrin as an organic carbon source and Tween-80 as an important element were further optimized, respectively. The high primary biodegradation of the Tween-80 by S. marcescens ECU1010 and its variant demonstrated their potential ability of degrading alkyl polyethoxylates to remove harmful nonionic surfactants from polluted effluents and streams. The optimal cultivation time for lipase biosynthesis was 24 h. These optimized compositions resulted in an economic production of lipase by S. marcescens ECU1010 var. UV-01, with a dramatically reduced cost (1/8–1/7 of the initial one) which is more suitable for industrial application.     

Production enhancement of Rhizopus arrhizus lipase by feeding oleic acid

A strategy for Rhizopus arrhizus lipase production enhancement by feeding oleic acid was developed. The oleic acid was proved to have strong inducing effect on lipase production, but high concentration oleic acid could repress lipase production. The decrease rate of oleic acid concentration using peanut oil as initial carbon source was figured out according to the change of oleic acid concentration in the fermentation broth. Our feeding strategy designed based on the decrease rate of oleic acid could avoid the repression of lipase production that is caused by high concentration of oleic acid in the fermenting liquor, and this strategy worked as a new feeding method showing excellent performance. The maximum lipase activity was gained by feeding dilute oleic acid every 12 h starting at 60 h, which maintained the oleic acid concentration around 18 mg/L, and the lipase activity was 31% higher than that of no feeding.     

S5 Lipase: an organic solvent tolerant enzyme

In this study, an organic solvent tolerant bacterial strain was isolated. This strain was identified as Pseudomonas sp. strain S5, and was shown to degrade BTEX (Benzene, Toluene, Ethyl-Benzene, and Xylene). Strain S5 generates an organic solvent-tolerant lipase in the late logarithmic phase of growth. Maximum lipase production was exhibited when peptone was utilized as the sole nitrogen source. Addition of any of the selected carbon sources to the medium resulted in a significant reduction of enzyme production. Lower lipase generation was noted when an inorganic nitrogen source was used as the sole nitrogen source. This bacterium hydrolyzed all tested triglycerides and the highest levels of production were observed when olive oil was used as a natural triglyceride. Basal medium containing Tween 60 enhanced lipase production to the most significant degree. The absence of magnesium ions (Mg2+) in the basal medium was also shown to stimulate lipase production. Meanwhile, an alkaline earth metal ion, Na+, was found to stimulate the production of S5 lipase.     

中温碱性脂肪酶的研究Ⅱ.扩展青霉PF868变株产酶条件

本文报道中温碱性脂肪酶高产变株扩展青霉（Ｐｅｎｉｃｉｌｌｉｕｍ ｅｘｐａｎｓｕｍ）ＰＦ８６８的产酶条件。研究结果表明ＰＦ８６８最适产酶条件为：碳源玉米粉,氮源黄豆饼粉,起始ｐＨ７．５,产酶培养温度２６℃,移种量１０％;亚适量的豆油有利于产酶;７００ｐｐｍ的泡敌不抑制菌丝生长且有利于产酶;适量的非离子表面活性剂Ｔｗｅｅｎ和Ｓｐａｎ类有利于菌丝生长和脂肪酶的释放。     

Citric acid production from cellobiose by 2-deoxyglucose-resistant mutant strains of Aspergillus niger in semi-solid culture

Citric acid production from cellobiose by Aspergillus niger was studied by a semi-solid culture method using bagasse as a carrier. From the parental strain Yang no. 2, mutant strains showing resistance to 2-deoxy-d-glucose (DG) on minimal medium containing glucose as a carbon source were induced. The representative mutant strain M155 was selected and subjected to further mutation. The new series of mutant strains showing resistance to DG on minimal medium containing cellobiose as a carbon source was induced, and among them the best mutant strain C192 showed higher citric acid productivity than Yang no. 2 in semi-solid culture when glucose was used as a carbon source. Moreover, in semi-solid culture, the strain C192 produced 49.6 g/l of citric acid, 1.6 times as much citric acid as Yang no. 2 produced, from 100 g cellobiose/l and showed enhanced -glucosidase production. In shake culture, the extracellular -glucosidase activity of C192 was higher than that of Yang no. 2 when not only cellobiose but also glucose and glycerol, catabolite repressors, were used as a carbon source. These results indicate that mutant strains such as C192 are insensitive to catabolite repression. Correspondence to: S. Usami     

脂解麻疯树油脂肪酶产生菌的筛选鉴定及其催化特性

[目的]分离筛选具有脂解麻疯树油能力的脂肪酶产生菌株,为以麻疯树油为原料酶法生产生物柴油奠定基础.[方法]以麻疯树油为唯一碳源,从麻疯树种子粉末处理过的土壤中分离筛选出1株具有脂解疯树油能力的脂肪酶产生菌,考察该菌株及其脂肪酶对有机溶剂耐受性以及脂肪酶催化酯化和转酯反应的能力,并通过生理生化特征和16S rDNA序列分...